You must be c_______ when you do your Maths homework.

You must be c_______ when you do your Maths homework. Be careful when you c_______ the street The heavy rain c_______ for two weeks,so many flights must be delayed. You must be strong . you must be You must be hungry You must be joking You must be confident. You must be dreaming you must be careful you must be ___!(kid) You must be carful next You must be happy oh., you must be joking,救命 You Must Be Strong 歌词 You must certainly be happy i must be cull you you must be mistaken是什么意思?